This invention relates to jewelry settings for gems, such as facet-cut diamonds.
Throughout history, gemstones such as diamonds have been cut and polished to form gems, and then set in rings, earrings and other objects to form jewelry. One cut that is currently popular for such gems is the round facet cut, or brilliant cut, shown in FIG. 1. This cut divides the gemstone 10 into an upper portion, known as the crown 11, and a lower portion, referred to as the pavilion 12. The circumference of the gem where the crown meets the pavilion is called the girdle 13. Another popular cut is the princess cut shown in FIGS. 2A and 2B. The princess cut gem 10′ also includes a crown 11′, a pavilion 12′ and a girdle 13′.
A variety of gem settings have been employed to securely hold gems in jewelry. One of the most popular types of gem settings is the channel type setting. One advantage of the channel setting is that this type of setting allows the gem to be set into the surface of a ring. The gems can be set all the way around the ring circumference, as often is done with anniversary rings, or partially around the ring circumference, as is done with some wedding and other rings.
With this type of setting, the jeweler cuts notches in each of the channel walls. The notches correspond to the girdle of the gem. The jeweler then places the gem in the notches, so that the girdle of the gem rests in the notches. The portions of the walls above the notches are then bent over the crown of the gem with jeweler's pliers. With this type of setting, the notches must be carefully aligned on the channel walls so that they will hold the gem at a level position. Also, the shape of the notches must be carefully cut with hand tools, such as a motorized bur, to match the shape of the gem girdle. Thus, this type of setting can be used only by a skilled jeweler. In addition, much time is required to set all of the gemstones in the ring, particularly if the gemstones are provided around the entire circumference of the ring.
Some manufacturers have created a shelf in each of the channel walls. In this type of setting, the gem is rested only on the shape of the shelf. The remainder of the wall, particularly the portion of the wall extending above the shelf, is not used to help hold the gem in the channel. Thus, the gem will not be securely held in the setting, and turning the ring upside down (for example, to place gems around the entire circumference of the ring) will result in the gem falling out unless the gems are held in place, for example, with beeswax.